Effect of the Afterglow on the Felting Shrinkage of Wool

Abstract

The so-called afterglow area of electric glow discharges, even if it does not emit visible radiation, still contains active particles capable of initiating a multitude of chemical reactions. When wool was exposed to the afterglow of various gases, a considerable amount of shrinkproofing effect (SPE) was observed. Quantitatively the effect was lower than that obtained in the actual glow. However, depending on the reaction variables (power, gaseous media, and reactor design), active particles were found as far as 300 mm downstream of the glow. The effect increases with the power, almost linearly, without an increase in the temperature. Therefore, in contrast to the glow, the afterglow does not singe the yarn at higher power values. These findings supplement our present theory on the species in glow discharges responsible for shrinkproofing wool. Since the electron density of the afterglow is zero, for practical purposes, free radicals and/or activated molecular species must play an important part in this type of shrinkproofing process. The effect caused by the actual glow is the combination of the high-energy electrons, ions, and other nonionic active species. The quantitative contribution of these various particles to the final SPE is still uncertain.